ObjectiveTo investigate the effect of low-dose, slow-release aspirin in reducing the incidence and/or severity of pregnancy complications in women identified as high risk of developing problems associated with uteroplacental insufficiency, namely pre-eclampsia or delivering a small-for-gestational age (SGA) baby.

DesignA prospective, randomized management study. One thousand and twenty-two women of mixed parity underwent color flow/pulsed Doppler (CFPD) imaging of the uterine arteries at the time of the 17–23 week (mean 19.9) anomaly scan. Women who were screen positive were randomized to a control or treatment group. The treatment group was given 100-mg slow-release aspirin (Disprin CV) daily and followed up at regular intervals. Women in the routine group received routine antenatal care. Main outcome measures were pre-eclampsia and SGA < 3rd centile. Secondary outcome measures were: SGA < 10th centile, pre-eclampsia requiring delivery before 34 weeks, placental abruption, an Apgar score < 7 at 5 min, admission to neonatal intensive care unit or a pregnancy that resulted in a stillbirth or neonatal death. Odds ratios (OR) with 95% confidence intervals (CI) were calculated for severe and any complications.

ResultsTwo hundred and sixteen women were screen positive according to the defined criteria. One hundred and three women were assigned to the treatment group and 113 to the control group. The difference in the incidence of pre-eclampsia and SGA < 3rd centile between the control and treatment groups did not reach statistical significance. There was a statistically significant reduction in any (OR 0.41 (CI 0.35–0.45), P < 0.01) and severe pregnancy complications (OR 0.43 (CI 0.21–0.84), P < 0.05) in the treatment group compared with the controls.

ConclusionsThe administration of slow-release aspirin to women identified as high risk, using color Doppler imaging of the uterine arteries at 20 weeks’ gestation, did not significantly alter the incidence of pre-eclampsia or delivery of a SGA baby. It did, however, improve the outcome by reducing the overall incidence of complications associated with uteroplacental insufficiency.